Endless magnetic tape cartridge and recording play-back instrument mounting same



Jan.'22, 1957 G. H. EASH 2,778,880

ENDLEss MAGNETIC TAPE CARTRIDGE AND RECORDING PLAY-BACK INSTRUMENTMOUNTING sAME Filed Aug. 4, 1955 2 Sheets-Sheet l 30 29 27 32 K f f 32 3fr): n 36 y f i,33 l1.--

GEORGE H. EASH ATTORNEY Jan. 22, 1957 H- EASH 2,778,880

ENDLESS MAGNETIC TAPE CARTRIDGE AND RECORDING PLAY-BACK INSTRUMENTMOUNTING SAME Filed Aug. 4, 1955 2 Sheets-Sheet 2 INVENTOR.

GEORGE H EASH @JJM ATTORNEY United States Patent O ENDLESS MAGNETIC TAPECARTRIDGE AND RECORDING PLAY-BACK INSTRU- MENT MOUNTING SAME George H.Eash, Toledo, Ohio, assignor to The Toledo Trust Company and Charles I.Poulsen, coexecutors of the estate Voli George H. Poulsen, deceasedApplication August 4, 1955, Serial No. 526,406

8 Claims. (Cl. 179-100.Z)

This invention relates to an endless magnetic tape cartridge and itsmounting on a recorder-playback instrument. i

An object is to produce a novel cartridge having a relatively largeendless roll of'magnetic tape, such for example as would make possiblethe playing or recording for the period of an hour or more, thecartridge being self contained with a small loop portion of the tapeexposed for engagement by the driving capstan and transducer of theassociated instrument and there being means for eliminating orcompensating for the harmful effects of static electricity generated bythe relative movement of adjacent tape convolutions when the cartridgeis in use.

Another object is to produce a new and improved brake or restrainingdevice for the tape reel, which is effective normally to hold the reelstationary when not in use but, which is automatically released to freethe reel when the cartridge is mounted in position of use on therecording-playback instrument.

A further object is to simplify and improve the construction of thecomponent parts of the magnetic tapecontaining cartridge for obviatingdifficulties of the tape fouling and for enabling simple and convenientassembly of the parts. y

A still further object is to enable different size cartridges of theabove character to be mounted on the recordingplayback instrumentwithout effecting any changes or adjustments either in the cartridge orin the instrument.

A still further object is to produce in combination with a magnetic tapecartridge, mechanism on the recordingplayback instrument whichaccommodates the same for urging the cartridge against the drivingcapstan and transducer head so that so long as the instrument is inoperation, the cartridge is positively retained in position of use.

A still further object is to produce mechanism on the recording-playbackinstrument, which, when switched to its on or play position,automatically operates parts for positively engaging the cartridge andresiliently urging same to position of use. l i

Other objects and advantages will hereinafter appear and for purposes ofillustration but not of limitation, an embodiment of the invention isshown on the accompanying drawings in which Figure 1 is a top plan viewof the magnetic tape cartridge, a portion -being broken away forpurposes of f clarity;

Figure 2 is a transverse `sectional view substantially on the line 2 2of Figure 1;

to urge the cartridge to playing position when the instrument isoperated; Y

Figure 6 is a view substantially on the line 6-6 of Figure 5 showing thetape cartridge engaging finger;

Figure 7 is a View substantially on the line 7--7 of Figure 5; and YFigure 8 is a view substantially on the line 8--8 of Figure 5.

The illustrated embodiment of the invention, particularly as shown onFigures l to 3, comprises a magnetic tape cartridge 10 for use onrecording-playback instruments either to record music, voices or thelike or to reproduce such sounds which have been previously recorded, aswill be readily undersoood by those skilled in this art. The cartridgein this instance is in the form of a substantially rectangular housingvof relatively shallow depth and is formed of suitable transparentplastic. As shown, the housing has a flat bottom panel ll'with which areformed integral side walls disposed at right angles to the bottom walland extending completely around the bottom wall to enclose same, exceptfor cut-outs as will hereinafter appear. Y

Forming a cover for the housing which may be adhered to or otherwisesuitably fixed to the upper edges of the side walls 12 is a flat coverpanel 13 arranged in parallel relationship to the flat bottom wall 11.Both thercover panel 13 and bottom panel llvare imperforate except Vthata pivot post extends through an aperture-in the bottom panel as willhereinafter appear. Disposedvsubstantially centrally of the bottom wall11 is an upstanding boss 14 and a metallic spacing washer 15 on the bosstits over a cylindrical post 16 which has a press fit through the boss14 and extends upwardly terminating short of the cover panel 13 toprovide a pivot post or axle for the tape reel as willhereinafter'appear.

Forming part of the rotatable tape reel is a at annular disk 18 whichhas an integral centrally disposed upstanding hub 17 which rests uponthe washer 14 and rotatably tits the post 16. The disk and its hub arealso of plastic material and resting upon the'reel disk 18 is an endlessspiral coil or roll of magnetic tape`19. Forming the hub of the tapereel is a cup 20also of plastic material which has a at bodyprovidedwith a central aperture tting the cylindrical hub 17 of the disk 18 anda peripheral circular wall 20`which inclines upwardly and outwardly fromthe body portion of the cup. The body of the cup abuts flatly againstthe disk 18 and the top of the circular wall 20 terminates short of thecover panel 13 allowing a narrow space between the underside of thecover panel 13 and thewall 20. The cup 'V20 is detachably secured to thehub 17 by a hairpin shaped spring V22 which has snap engagement in agroove 23 formed in the outer surface of the hub 17. Manifestly byopening the spring 22, it may be 'slipped from the hub to-release thecup 20. This provides an exceedingly simple and convenient assemblywhich lends itself to economical production.

i Mounted on the upper surface of the' reel disk 18 are equidistantlyspaced radially disposed graphite strips or rods 24 which projectslightly above the surface of the disk and upon which the lower edge ofthe tape coil 19 rests. These rods may be adhesively secured to the diskand are of such'length as-tolenable the lower edges of all of the tapelconvolutions to rest thereupon. strips orprods are for the purpose ofeliminating or dissipating static electricity generated during theoperation of the reel and caused by the relative movement of adjacentconvolutions. Reference is hereby made v' to` my copending application,Serial No. 446,903, filed July 30, 1954, and entitled Endless MagneticTape Cartridge where a more complete description thereof is set forth.

Depending from the underside and integral with the These avranno 3 coverpanel 13 are curved `sectional angeor wall members 25 which terminateshort of the reel disk 18 and are arranged closely adjacent theperipheral portion. These .flanges conform generally to the .curvatureof the outside of the tape coil and are disposed in relatively closejuxtaposition thereto. The space between adjacent angerd sectionsaccommodate the guide-rods and a portion of the magnetic tape as willhereinafter appear.

Extending through spaces between flange sections are guide wires 26 and26'Vwhich are disposed on opposite sides and in close relation to theupper ends of the walls 21 of the cup or hub Ztl and are suitablyanchored at theirl opposite ends to posts yor retaining members 27attached by screws to the base wall or panely 11. AThe guide wire oryrod 26 has a curved. depressed portion 26a (Figure 3) which is adaptedto engage the upper edges of/ the innermosty convolutions of .the taperolls.` These guide wires orv rods serve. to militate against the tapeconvolutionsrising from, the plane ofthe tape roll away from thegraphite strips 24, Vtheaction being that when a convolution. rises fromthe., plane `of the upper edge of the tape roll and engages4 one ofthese guide rods, such convolutions. during the ,rotation of the reel isironed back toward and into engagement with the graphite strips therebyto insure that all portions of the tape roll engage the graphite stripsfor dissipating or equalizing any static charges developed during theoperation of the tape roll.

The guide rod, 26 also serves as a guide over which the tape from theinside of thetape roll passes so that it is spaced slightly from theupper edges of thetape convolutions and enables such Iportion of thetape to pass freely from the spiral roll. Thence the tape passes througha space between anged sections 25 and over anl upstanding plate guide 28which is attached to and rises from the base panel 11, to a guide postor cylinder 30 mounted atnoneside .of and at the front of a base panel11. It will be understoodthat a tape ,loop 29 is provided andl whichextends along and parallel to the front wall 12 of the cartridge, aguide cylinder 31 being disposed at ,thek opposite side of the cartridgeupon the base panel 11 and about which the loop 29 passes. In thisinstance there are lthreecutouts at the front of the cartridge, oneaccommodating the guide cylinder 31 and enabling the driving capstan ofthe recording-playback instrument to engage the tape for driving thesame. One of the cutouts serves to afford. access to the tape by theVtransducer head asV will also hereinafter appear.

The flange section 25 adjacent. the guide cylinder 31 is formed with anintegral` extension 31a which terminates adjacent the cylinder 31 and,assists, in guiding the loop from the cylinder 31 to the, outside of thetape roll. It will also he noted that the next adjacent flange sectionhas an outwardly yinclined extension 31b which5 alsol serves to guidethe loop from the guide cylinder ,31.7, Thus` both sides of the loop areguided as it passes from the guide cylinder 31 to the periphery of thetape roll and militates against portionsy of the loop being fouled asfor `example by being jammed between the reelvand housingrwalls. A

Means are providedv to restrain the tape reel from movement when itisnot in use and for this purpose an elongate slot 33 .is formed in thebase panelV 11 of the cartridge adjacent. the,y guide cylinder 3l andsubstantially diametrically aligned with that cylinder. `A spring arm 34has one end secured to an anchor lugV 35 xed to the base panel 11 andsuitably connected to the free end of the spring arm 3,4 is a shoe 3ewith which is integral a substantially inverted L-shaped arm 37, the endportion of which transversely spans the slot 33. Integral with the shoe36 is, an inwardly extending lug or tooth 38 which is adapted to enter`-one or another of an annular series of notches 39 Iextending completelyaround and formed onthe periphery of thedisk or reel plate 18. Thusnormally the tooth 38 engages in a notch 39 d to hold the tape reelstationary, the spring 34 normally urging the tooth into notchengagement. As will hereinafter appear, the tooth 38 is automaticallymoved away from engagement with a notch 39 when the cartridge is mountedon the recording-playback instrument and the latter operated.

The recording-playback instrument particularly designed to accommodatethe cartridge above described is generally designated at 4G and has atoppanel 41 suitably attached to a substantially rectangular box. tSillacontaining the usual electrical equipment required for operating andrecording on or reproducing from the magnetic tape but since the sameforms no part of the present invention, description'andillustrationthereof are not'deerned necessary. Suitably secured to the top panel 4iabout midway of its length is a flanged guide 42 providing an elongateguide strip against which one side of the tape cartridge 1t) is adaptedto abut. Shown by broken lines on'Figure 4 are two tape cartridges 10designating the larger cartridge and lila the smaller cartridge,V thusindicating that the instrument can handle different size cartridgeswithout change or adjustment.

Near the front of the guide 42 and spaced inwardly therefrom is a drivecapstan 43 which is a rotating cylinderjdriven by a suitable electricmotor (not shown). The drive cap'stan is adjacent a transducer head 44and both the capstan and transducer head are adapted to extend into twoof the cutouts 32'` respectively as above described in connection withthe tape cartridge. Substantially in alignment with the transducer headand drive capstan is a stop pin 45' against which the front end of thecartridge abuts in order correctly to position it relative to theoperating members.

Directly in rear of the drive capstan is an elongate slot i6 with whichthe slot 33 of the tape cartridge is adapted to register. Having aportion of its upper' end extending through the slot 46 is a trigger 47which is adapted to extend. into the slot 33 of the tape cartridge toengage the end portion 37 of the brake shoe 36 successively to releasethe brake and free the tape reel and urge the guide cylinder 31 againstthe drive capstan 43. Thus the tape is pinched between the drive capstanand the guide cylinder for imparting translatory movement to the tapeloop as will be readily understood.

As shown in Figures 5 and 6 the trigger 47 constitutes a verticallydisposed ringer, the upper end of which is hooked and the lower end ofwhich is integral with a horizontally disposed h-shaped lever arm 43.The arm 4S is'rpivotedV at 49 and is urged in a clockwise direction(Figure 5)' by a helical spring 5h one end of which is hooked toA thefree end portion of the arm 43 and the opposite end of which is hookedto an intermediate portion of a relatively long control arm 51. The arm5i is pivoted at one end as indicated at 52 and for limiting suchtensicned movement of the arm 48 a stop 53 is arranged to be engaged bythe free end portion of the arm 48.

The operating end of the trigger. e7 is lifted vertically so that itwill extend upwardly and forwardly through the slot 46 and into the slot53 of the cartridge and this action is caused by a cam arm 54 (Figures 5and 7). One end of the arm 54 is secured to `an anchor p ost 55 and thefree end of the arm Se has an upwardly curved cam end portion 54a overwhich the arm 4S rides when it is moved towardthe stop 53: by the springSi?.

The free'end portion of the elongate arm Si has an inclined cam surface57 which terminates in a notch Disposed beneath the L-shaped arm 4S is acontrol lever 59 which is intermediately pivoted on a pin 62 and has anoperating knob et?, a portieri of which extends through an arcuate slot61 in the top panel 41 of the instrument 4t). A portion of the knob@disposed beneath the panel 41. engages the cam surface 57'so that lwhenthe knob 6% is, movedfrom its off to its on positioinit may enter thenotch 58 to retain the parts in this position. Such agresse over the cam54a to lift the trigger 47 and at the same When the operating knob 60 isin its oi position 1 an upstanding tlange 63 integral with thefoppositeend of the control lever 59 provides a stop for limiting any clockwisemovement of the arm 48, there being a stepped notch 64 (Figure 8) in theange 63 to receive the end of the arm 48 and hold it against suchclockwise movement, However, the movement of the knob 60 to its onposition moves the ange 63 away from the arm 48 to allow the latter torock and enable the trigger 47 to be moved as above explained.V Themovement of the operating knob 60 back to its oi position relieves thetension on the spring 50 and the rocking engagement of the control lever59 to the position shown by full lines in Figure 4, enables the flange63 to rock the L-shaped arm 43 back to its original position, the lattermoving off from the cam 54a so that the trigger retracts from the slotstoan inoperative `out-of-the-way position.

It will be apparent that I have produced an exceedingly simple andecient magnetic tape cartridge which can handle much greater length oftape than has heretofore been possible in a single cartridge and withoutthe necessity of threading the tape from one reel to another asordinarily required by most recording-playback instruments. The endlesstape is so mounted that it has free and unrestricted movement,eliminating troublesome piling up of tape which has heretofore notinfrequently occurred. The dissipation or equalization of staticelectricity generated during the operation of the tape reel is also ofimportance. A feature of outstanding importance is the adaptation of thecartridge to the instrument so that dierent size cartridge can beapplied to the same instrument. The mechanism on the instrument is suchas to hold the cartridge in playing position without the necessity ofmaking adjustments other than the actuation ot the operating switch knobto the play or on position.

Numerous changes in details of construction, arrangement and operationmay be eifected without departing'v from the spirit of the invention,especially as defined in the appended claims.

What I claim is:

l. in a single-reel magnetic type cartridge for use with a recordingplay-back machine ofthe type having drive means for lengthwise advancingthe tape in one direction past a transducer head: a housing havingspaced top and bottom walls and having an open end; a reel mounted inthe housing for rotation on an upright axis, said reel having a coaxialhub and having a flange at one end of the hub normal to the reel axisand iiatwise overlying the bottom wall of the housing; an endlessspirally coiled roll of magnetic tape on said reel encircling the hub.

thereof and edgewise supported by saidflange, said roll having a loop oftape projecting therefrom toward the open end of the housing with oneportion of the loop projecting from the convolution atpthe outerdiameter of the roll, another portion of the loop projecting from theconvolution at the inner diameter of the roll and an intermediateportion of the loop being exposed at the open end of the housing forcooperation with the drive means Vand transducer head of a recordingplay-back machine which is to receive the cartridge so that lengthwiseadvancing motion may be imparted to the loop to effect stripping of tapefrom the inner diameter of the roll and rotation of the reel in thedirection to wind up tape on the outer diameter of the roll; a series ofelongated graphite strips substantially radially mounted on the reelange andprojecting slightly from the upper face thereof to be engaged bythe lower edges of the tape convolutions for spacing the same from theadjacent face of the ange, said strips providing for lubricating thetape convolutions as a consequence of the abrasive action of theconvolutions thereupon produced by relative lengthwise movement of theconvolutions relative to one another and to the reel which results fromwinding up the tape onta `diameter of the roll larger than that at whichthe tape is stripped from the roll; an elongated guide member carriedby` the housing, said guide member extending across the upper face ofthe roll of tape closely adjacent tothe upper edges of the rollconvolutions and substantially tangent to the inner diameter of theroll, said guide member being positioned to act upon convolutions of theroll that may creep upwardly into contact therewith in a lmanner todirect such convolutions downwardly into edgewise engagement with saidgraphite strips to assure lubrication of the convolutions anddissipation of static charges on the tape generated by the relativemotion between the roll convolutions, and wall means extending about theperipheral edge of the reel for preventing the tape from fouling, saidwall means including a pair of side by side extension walls for conningthat portion of the tape passing from the loop to the outer diameter ofthe roll.

2. In a single-reel magnetic type cartridge for use with a recordingplay-back machine of the type having drive means for lengthwiseadvancing the tape in one direction past a transducer head: a housinghaving spaced top and bottom walls and having an open end; a reelmounted in the housing for rotation on an upright axis, said reel havinga coaxial hub and having a flange at one end of the hub norm-al to thereal axis and atwise overlying the bottom wall of the housing; anendless spirally coiled roll `of magnetic tape on said reel encirclingthe hub thereof and edgewise supported by said flange, said roll having-a loop of tape projecting there from toward the open end of the housingwith one portion ofthe Iloop projecting from the convolution at theouter diameter of Athe roll, another portion of the loop projecting fromthe convolution `at the inner diameter of the r-oll and an intermediateportion vof the loop being exposed at the open end of the housing forcooperation with Ithe drive means `and transducer head of a recordingplay-back machine which is to receive the cartridge so that lengthwiseadvancing motion may be imparted to the loop to eiect stripping of tapefrom the inner diameter of the roll and rotation of the reel in thedirection to wind up tape on the `outer diameter of kthe roll; a seriesof elongated graphite strips substantially radially mounted on the reelflange and projecting slightly from the upper face thereof t-o beengaged by the lower edges of the tape convolutions for spacing the samefrom the adjacent face of lthe flange, -s'aid strips providing forlubricating fthe `tape convolutions as a consequence of the abrasiveaction of the convolutions thereupon produced by relative lengthwisemovement of the convolutions relative to one another and to the -rcelwhich results from winding up the tape on a diameter of the roll largerthan that at which the tape is stripped from the roll; an elongatedguide member carried by the housing, said guide member extendingacross'the upper face of the roll of tape closely adjacent to the upperedges'of Ithe roll convolutions and substantially tangent to the innerdiameter Iof the roll, said guide member 'having a downwardly bowedintermediate portion Ito act upon convolutions of the roll ,that maycreep upwardly into contact therewith in a agresse 7 said wa-lljn'ieansincluding arpair walls' fori corrn'ing that poi-- from the loop to theouter the l tape from fouling? of side by side'fextensl non of thtapepassing diameter of the roll l 3. In 'a single-reel magneti-c typecartridge for use with a recording play-back ymachine of the ,typeVhaving drive means for lengthwiseI advancing the tape in one directionpast a transducer head: a housing having spaced y ltop and bottom wallsand having an open end; a reel mounted in the k'housing for rotationonan upright axis, said reel having a coaxial hub and having a separateflange structure fitting said hub, fastener means' detachably securingsaid iia'nge'structure to said hub; arrendless spirally coiledV roll ofmagnetic tape on said reel encircling the Ahub thereof arid e'dgewisesupported by said ange, lsaid roll having a loop of tape projectingtherefrom toward the `open end of Vthe housing with one portion of theloop projecting' from the convolution' at the vouter diameter ofv theroll, yanother portion of the lloop projecting from the convolution atthe inner diameter of :the roll and an intermediate portion of the l-oopbeing exposed at the open end of the housing for cooperation with thedrive means and transducer head of a recording play-back machine whichis to receive the cartridge so that lengthwise advancing motion may beimparted to the loop to eifect stripping of tape from the inner diameterof the roll and rotation of the reel in the direction to wind up tape onthe outer diameter of the roll; a series of elongated graphite stripssubstantially radially mounted on the reel ange and projecting slightlyfrom ,the upper face thereof Ito be engaged by the lower edges ofthe'tape convolutions for spacing the same from the adjacent face of theflange, said strips providing for lubricating the tape convolutiong as aconsequence of the abrasive act-ion 'of the convolutions thereuponproduced by relative lengthwise movement of the convolutions relative`to one another and to the reel which results from winding up they tapeon a diameter of the roll larger than that at which the tape is strippedfrom the roll; anv elongated guide member carried by the housing, said4guide member extending across the upper face ofthe roll of tape closelyadjacent to the upper edges of the roll convolution'g and substantiallytangent to the inner diameter of 4the roll, said guide member beingpositioned to act upon convolutions oi the roll that` may creep upwardlyinto contact therewith in a manner to direct such convolu- 'tionsdownwardly into edgewiseV engagement with said graphite strips to assurelubrication of the convolutions and dissipation of static charges on thetape generated by the relative motion between the roll convolutions, andwall means extending `about the peripheral edge of .the reel forpreventing the tape from fouling, said wall means including a pair ofside by `side extension walls for confining that portion Aof the tapepassing from the loop to the outer diameter of the roll.

4. Inna single-reel magnetic type cartridge for use with a recordingplay-back machine `of the `type having drive means` for lengthwiseadvancing Vthe tape in one direction past a transducer head: a housinghaving spaced top and bottom walls, and having an open end; ra reelmounted in lthe housing'for 'rotationon an upright axis, said reelhaving a coaxial hub and having a angc; an endless spirally coiled rollof magnetic tape on said reel encircling the hub thereof and ed'gewisesupported by said flange, saidroll yhaving a loop of tape projectingtherefrom toward the open end of the housing with one portion of theloop projecting from the convolution at the outer diameterl of the roll,another portion of the l loop projecting from the convolution at theinner diameter ofgthe roll and an intermediate portion of the loop beingexposed at the open end ofthe 'housing for cooperation with the drivemeans and transducer head of aprecording play-back machine whchis toreceive the cartridge so that lengthwise advanei'ng mmtion may beimparte'dfto the'ioop to effect strippingV of tape 'from the'irrnerfdiarneterof"the rolll'an'd`r rotation' of the reel in thedirection'toV wind'up tap'e on the outer diameter of the roll; a seriesIof elongated graphite strips substantially' radially mounted on' thereel flange and projecting slightly fromV the upper face thereof to beengaged by the lower edges of the tape convolutions for spacing the samefrom the adjacent face of the ange, said strips providing forlubricating the tape convolultions as a consequence of the abrasiveaction of the convolutions thereupon produced by relative lengthwisemovement of the convoiutions relative to one another and 'to the `reelwhich results from Winding up the tape on a diameter tof the roll larger4than that at which the tape is stripped from-the roll; an elongatedguide member carried by the housing, s aid guide member extending acrossthe upper face' of the roll of tape closely adjacent 'to the upper edgesof the roll convolutions and substantially tangent to the inner diameterof the roll but positioned beneath said other portion of the loop whichprojects from the inner diameter of the roll to `guide they tapestripped from the roll and constrain it to travel flatwise over theupper face of the roll in `spaced relation thereto, said guide memberbeing posit-ionc'd to act upon convolutions of the roll that may creepupwardly into contact therewith in a manner to direct such convolutions`downwardly into edgewise engagement with said graphite stripsY toassure lubrication of the' convolutions and dissipation of staticcharges on the tape generated' by the relative motion between the rolloonvolutions, and a second guide member on the opposite side of said huband having an intermediate downwardly bowed portion ito act upon theinnermost convolutions of the roll.

5. In a single-reel magnetic type cartridge for use with a recordingplay-back machine of the type having drive means for lengthwiseadvancing the tape in one direction past a tranducer head: a housinghaving spaced top and bottom walls and having an open end; a reelmounted in the housing for rotation on an upright axis, said reel havinga coaxial hub and having a flange; an endless spirally coiled roll ofmagnetic tape on said reel encircling the hub thereof and edgewisesupported by said flange, said roll having a lloop of tape projectingtherefrom toward the open end of the housing with one portion of theloop projecting from the convolution at the outer diameter of the roll,another portion of the loop projecting from the convolution at the innerdiameter of the roll and an intermediate portion of the loop beingexposed at the open end of the housing for cooperation with the drivemeans and transducer head of a recording play-back machine which is toreceive the cartridge so that lengthwise advancing motion may beimparted to the loop to effect stripping of tape from the inner diameterof the roll and rotation of the reel in the direction to wind up tape onthe outer diameter of the roll; a series of elongated graph- Y itestrips substantially radially mounted on the reel flange and projectingslightly from the upper face thereof to be engaged by the lower edges ofthe tape convolutions for spacing the samel from the adjacent face ofthe ange, said strips providing for iubricating the tape convolutions asa consequence of the abrasive action of the convolutions thereuponproduced by relative lengthwise movement v of the convolutions relativeto one another and to the i'. reel which results from winding up thetape on a diameter of the roll larger than that at which the tape isstripped from the roll; and elongated guide member carried by thehousing, said guide member extending across the upper face of the rollof tape closely adjacent to the upper edges et' the roll convolntionsand substantially tangent to the inner diameter of the roll butpositioned beneath said other portion of ythe loop which projects fromthe inner diameter of the roll to guide the tape stripped-from the rolland constrain it to travel'flatwise over the upper face of the roll inspaced relation thereto, said guide member being positioned to act uponconvolutions of the roll that may creep upwardly into contact therewithin a manner to direct such convolutions downwardly into edgewiseengagement with said graphite strips to assure lubrication of theconvolutions and dissipation of static charges on the tape generated bythe relative motion between the roll convolutions, an annular series ofnotches on the peripheral edge of the reel, a spring-tensioned toothmember normally engaging a notch to restrain the l reel from turning, aslot in the bottom wall, and an arm on said tooth member accessiblethrough said slot for releasing the member from the notched periphery.

6. In combination with a recording play-back instrument having arotatable drive capstan and a transducer head arranged closely in a row,an endless magnetic tape cartridge comprising a housing closed exceptfor openings to receive said capstan and transducer head, a singlespiral roll of tape Within said housing having a loop guided to passsaid openings and fed from the center of the roll and delivered to theoutside of the roll, a rotatable reel in the housing supporting saidroll, an elongate slot in the bottom wall of the housing, a lingercarried by said instrument to enter said elongate slot and movable tourge the cartridge into operative engagement with said capstan andtransducer head, and means for actuating said finger for effecting suchmovement.

7. In combination with a recording play-back instrument having arotatable drive capstan and a transducer head arranged closely in a row,an endless magnetic tape cartridge comprising a housing closed exceptfor openings to receive said capstan and transducer head, a singlespiral roll of tape within said housing having a loop guided to passsaid openings and fed from the center of the roll and delivered to theoutside of the roll, a rotatable reel in the housing supporting saidroll, a springtensioned brake operating against the reel for normallyrestraining same from turning, an arm connected to said brake, anelongate slot in the bottom wal'l of the housing through which access tosaid arm is had, a finger carried by said instrument to enter saidelongate slot and movable to engage said arm for releasing said brakeand then to urge the cartridge into operative engagement with saidcapstan and transducer head, and means for actuating said finger foreecting such movement.

8. In combination with a recording play-back instrument having arotatable drive capstan and a transducer head arranged closely in a row,an endless magnetic tape cartridge comprising a housing closed exceptfor openings to receive said capstan and transducer head, a singlespiral roll of tape Within said housing having a loop guided to passsaid openings and fed from the center of the roll and delivered 'to theoutside of the roll, a rotatable reel in the housing supporting saidroll, a springtensioned brake operating against the reel for normallyrestraining same from turning, an arm connected to said brake, anelongate slot in the bottom Wall of the housing through which access tosaid arm is had, a finger carried by said instrument to enter saidelongate slot and .movable to engage said arm for releasing said brakeand then to urge the cartridge into operative engagement with saidcapstan and transducer head, a control member for said instrumentmovable between operative and inoperative positions, and a series ofmeans between said control member and linger whereby operative movementis imparted to the nger when the control member is moved to inoperativeposition.

References Cited in the tile of this patent UNITED STATES PATENTS ThadOct. 28, i952

